| 摘要 |
PURPOSE:To form a cap oxide film coating the upper surface of a trench capacitor without giving any stress to a substrate by a method wherein a trench is shaped to the single crystal semiconductor substrate, an oxide film is formed into the trench, the inside of the trench is buried with a polycrystalline semiconductor layer, epitaxial growth is conducted, an insulating layer is shaped onto the polycrystalline semiconductor layer and an element is formed to a single crystal layer. CONSTITUTION:A cap insulating film is shaped by burying a recessed section formed to an epitaxial layer 9 through photoetching with a CVD oxide film. That is, an SiO2 layer 6 is removed through etching and an epitaxial layer 2 is exposed, and the N-type Si layer 9 is grown in an epitaxial manner. A single crystal is not grown to the upper section of a trench at that time, a polycrystalline section 23 is formed. The epitaxial layer 9 at a position where an SiO2 layer is buried subsequently is removed through photoetching. The SiO2 layer is grown onto the whole surface, the surface is flattened through etchback, and an SiO2 layer 10 is buried into the recessed section in the epitaxial layer 9. Accordingly, stress is not applied to a substrate in the upper section of the trench.
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